Human Stem Cells for Ophthalmology: Recent Advances in Diagnostic Image Analysis and Computational Modelling.

Purpose of Review: To explore the advances and future research directions in image analysis and computational modelling of human stem cells (hSCs) for ophthalmological applications. Recent Findings: hSCs hold great potential in ocular regenerative medicine due to their application in cell-based therapies and in disease modelling and drug discovery using state-of-the-art 2D and 3D organoid models. However, a deeper characterisation of their complex, multi-scale properties is required to optimise their translation to clinical practice. Image analysis combined with computational modelling is a powerful tool to explore mechanisms of hSC behaviour and aid clinical diagnosis and therapy. Summary: Many computational models draw on a variety of techniques, often blending continuum and discrete approaches, and have been used to describe cell differentiation and self-organisation. Machine learning tools are having a significant impact in model development and improving image classification processes for clinical diagnosis and treatment and will be the focus of much future research.

Patient-reported outcome measures for a large cohort of serum eye drops recipients in the UK.

INTRODUCTION: Serum eye drops (SED) are an important treatment for patients with chronic and severe ocular surface disease (OSD). Despite a long history of use, there is a paucity of information on patient-reported outcomes, particularly comparing autologous SED (Auto-SED) and allogeneic SED (Allo-SED). National Health Service Blood and Transplant is the national provider of SED service for patients in the UK. PURPOSE: To evaluate and compare patient-reported outcome measures (PROMs) in patients receiving Auto-SED and Allo-SED for severe OSD. MATERIALS AND METHODS: PROMs were retrospectively collected from all new patients commencing treatment with Auto-SED and Allo-SED between January 2017 and September 2018, using the Ocular Surface Disease Index (OSDI) 12-item questionnaire. A linear mixed model was used to evaluate the change in OSDI scores between baseline and follow-up. RESULTS: During the study period, 279 patients who received either Auto-SED (n = 71) or Allo-SED (n = 208) were included in the analysis. Baseline and follow-up OSDI scores were available for 161 of these (49 Auto-SED and 112 Allo-SED). There was a significant reduction in mean OSDI score for both Auto-SED (59.06-24.63, p < 0.001) and Allo-SED (64.21-34.37, p < 0.001). There was no significant difference between Auto-SED and Allo-SED patients in terms of the reduction in the OSDI score (p = 0.27). CONCLUSION: Both Auto-SED and Allo-SED were associated with improvements in the quality of life of patients with chronic and severe OSD. Auto-SED and Allo-SED were equally effective in relieving the symptoms of OSD.

Pathophysiology of aniridia-associated keratopathy: Developmental aspects and unanswered questions.

Aniridia, a rare congenital disease, is often characterized by a progressive, pronounced limbal insufficiency and ocular surface pathology termed aniridia-associated keratopathy (AAK). Due to the characteristics of AAK and its bilateral nature, clinical management is challenging and complicated by the multiple coexisting ocular and systemic morbidities in aniridia. Although it is primarily assumed that AAK originates from a congenital limbal stem cell deficiency, in recent years AAK and its pathogenesis has been questioned in the light of new evidence and a refined understanding of ocular development and the biology of limbal stem cells (LSCs) and their niche. Here, by consolidating and comparing the latest clinical and preclinical evidence, we discuss key unanswered questions regarding ocular developmental aspects crucial to AAK. We also highlight hypotheses on the potential role of LSCs and the ocular surface microenvironment in AAK. The insights thus gained lead to a greater appreciation for the role of developmental and cellular processes in the emergence of AAK. They also highlight areas for future research to enable a deeper understanding of aniridia, and thereby the potential to develop new treatments for this rare but blinding ocular surface disease.

A systematic review of cellular therapies for the treatment of limbal stem cell deficiency affecting one or both eyes.

PURPOSE: This systematic review (SR) assessed the efficacy, safety and cost-effectiveness of cell-based therapy to manage limbal stem cell deficiency (LSCD), a sight-threatening orphan condition most frequently associated with severe chemical or thermal burns. LSCD has historically been treated by transplanting limbal tissue. In 1997, a new treatment, cultured limbal epithelial autografts, was described for unilateral LSCD. In cases of bilateral disease cultured autologous oral mucosa stem cells have been used. The relative efficacy of different cultured tissue procedures is unknown. METHODS: A protocol was registered with PROSPERO (CRD42017081117). Searches were conducted in 14 databases and 6 conference websites. Two reviewers independently selected studies, conducted data extraction and assessed risk of bias. One reviewer extracted individual patient data (IPD); a second checked extracted data. Data were assessed to determine the feasibility of statistical analysis, with Bayesian synthesis used to estimate improvement achieved by different treatments. RESULTS: Fifty-two studies were eligible for inclusion (1113 eyes); 41 studies (716 eyes) reported IPD. No evidence was identified on cost-effectiveness. This SR was unable to confirm that any of the types of ex vivo cultured stem cell transplants identified for LSCD treatment were statistically superior when assessed against the outcomes of interest. CONCLUSIONS: We believe this SR is the first to include IPD analysis of LSCD data. There is no evidence for the superiority of any method of limbal stem cell transplant. Confirmation of the safety and efficacy of this treatment modality is challenging due to heterogeneity within and between the studies identified. Therefore, recommendations for future research are proposed.

Microbial keratitis in corneal grafts: predisposing factors and outcomes.

PurposeTo identify the nature of microbial keratitis in corneal grafts and the clinical outcomes at a tertiary hospital in the United Kingdom.Patients and methodsA retrospective case series of microbial keratitis in corneal grafts at the Royal Victoria Infirmary, Newcastle upon Tyne over a 17-year period (1997-2014).ResultsA total of 759 consecutive corneal grafts were identified from the Cornea Transplantation database. Of these, 59 episodes of microbial keratitis occurred in 41 eyes of 41 patients (5.4%; 19 male, 46.3%). Median patient age was 73 years (SD=19.4 years). The most common indication for corneal transplantation was bullous keratopathy (11/41, 26.8%). There were 34/59 (57.6%) episodes of culture-positive graft keratitis; Streptococcus pneumoniae and Staphylococcus aureus were each isolated in 5/34 (14.7%) culture-positive episodes. In all, 35/59 (59.3%) episodes of microbial keratitis occurred in 22 previously failed grafts and 3 de novo graft failures. Gram-negative keratitis was more likely to cause reduced BCVA after (χ2-test, P=0.02). Median graft duration was 49.5 months (SD=43.7 months). Failed grafts were significantly older (median 69 vs 27 months, P=0.009).ConclusionThis represents the longest published follow-up data on microbial keratitis and is the only of its kind in the United Kingdom. The incidence of 5.4% is comparable to that within the developed world. Graft age was significantly associated with graft failure in microbial keratitis; the ongoing risk of microbial keratitis warrants providing patients with long-term open access to hospital eye services.

Gamma-irradiated human amniotic membrane decellularised with sodium dodecyl sulfate is a more efficient substrate for the ex vivo expansion of limbal stem cells.

The gold standard substrate for the ex vivo expansion of human limbal stem cells (LSCs) remains the human amniotic membrane (HAM) but this is not a defined substrate and is subject to biological variability and the potential to transmit disease. To better define HAM and mitigate the risk of disease transmission, we sought to determine if decellularisation and/or γ-irradiation have an adverse effect on culture growth and LSC phenotype. Ex vivo limbal explant cultures were set up on fresh HAM, HAM decellularised with 0.5M NaOH, and 0.5% (w/v) sodium dodecyl sulfate (SDS) with or without γ-irradiation. Explant growth rate was measured and LSC phenotype was characterised by histology, immunostaining and qRT-PCR (ABCG2, ΔNp63, Ki67, CK12, and CK13). Ƴ-irradiation marginally stiffened HAM, as measured by Brillouin spectromicroscopy. HAM stiffness and γ-irradiation did not significantly affect the LSC phenotype, however LSCs expanded significantly faster on Ƴ-irradiated SDS decellularised HAM (p<0.05) which was also corroborated by the highest expression of Ki67 and putative LSC marker, ABCG2. Colony forming efficiency assays showed a greater yield and proportion of holoclones in cells cultured on Ƴ-irradiated SDS decellularised HAM. Together our data indicate that SDS decellularised HAM may be a more efficacious substrate for the expansion of LSCs and the use of a γ-irradiated HAM allows the user to start the manufacturing process with a sterile substrate, potentially making it safer. STATEMENT OF SIGNIFICANCE: Despite its disadvantages, including its biological variability and its ability to transfer disease, human amniotic membrane (HAM) remains the gold standard substrate for limbal stem cell (LSC) culture. To address these disadvantages, we used a decellularised HAM sterilised by gamma-irradiation for LSC culture. We cultured LSCs on fresh HAM, HAM decellularised with NaOH, HAM decellularised with sodium dodecyl sulfate (SDS) and HAM decellularised with SDS and sterilised with gamma-irradiation. We demonstrated that although HAM decellularised with SDS and sterilised with gamma-irradiation is significantly stiffer this does not affect LSC culture growth rate or the phenotype of cultured LSCs. We therefore recommend the use of SDS decellularised gamma-irradiated HAM in future LSC clinical trials.

Impulse oscillometry, spirometry, and passive smoking in healthy children and adolescents.

OBJECTIVE: To identify changes in the forced and quiet breathing parameters of lung function in healthy children and adolescents exposed to passive smoking (PS). METHOD: Comparative cross-sectional study. Healthy schoolchildren aged 6 to 14 years. We collected anthropometric data, lung function parameters using spirometry (forced breathing), and quiet breathing parameters using impulse oscillometry. The sample was divided into two groups according to exposure to PS: passive smoking group (PSG) and non-passive smoking group (NPSG). For the statistical analysis, the Shapiro-Wilk test was used to verify data normality and the T-test or Mann-Whitney test to compare spirometric and oscillometric parameters between groups (p≤0.05). MAIN FINDINGS: The study included 78 children and adolescents, with 14 boys and 25 girls in each group. There were differences in the mean values for peak expiratory flow (p=0.01). There were no significant differences between the groups in values for z-score and lower limit of normal. The PSG had higher mean absolute values for reactance area (X5=0.05) and significant percentage of predicted values for the following impulse oscillometry parameters: central airway resistance (R20%, p=0.03) and for the indicators of presence of airway obstruction (Fres%, p=0.01; X5%=0.01% and AX%, p=0.01). CONCLUSION: Children and adolescents exposed to PS had lower values for the spirometric variables and higher values for the oscillometric variables, indicating changes in forced and quiet parameters of lung function compared to the NPSG.

Pan-European survey of the topical ocular use of cyclosporine A.

OBJECTIVE: To assess medical practices surrounding the use of topical ocular cyclosporine A across European Union nations. METHODS: Key stakeholders (ophthalmologists, hospital pharmacists, regulatory health authorities) from European Union member states were interviewed by telephone using a semi-structured, open-ended questionnaire. Ophthalmologists responded to questions about practice patterns of cyclosporine A use (prescription frequency, indication, dosage), pharmacists about cyclosporine A formulations (composition, manufacturing process, quality control, distribution), and the regulatory authorities about market authorization and pharmacovigilance for various cyclosporine A products. RESULTS: Over the years, cyclosporine A use for ophthalmic indications has increased across all European Union nations. Prevalence of cyclosporine A use was heterogeneous, with Belgium, France, Germany, Italy, Portugal, Spain and the United Kingdom reporting the highest frequency. Compounded cyclosporine A formulations and other cyclosporine A products were prescribed through temporary authorization on a compassionate use or named-patient basis. Cyclosporine A was prescribed for dry eye disease, atopic and vernal keratoconjunctivitis, corneal graft rejection, and other autoimmune and inflammatory diseases. Concentrations of prescribed topical cyclosporine A ranged between 0.05-2% and formulations were instilled 1-6 times daily. Interviewed stakeholders expressed concern regarding, (1) paucity of product information, (2) lack of standardized manufacturing processes and quality control of cyclosporine A formulations, and (3) poor regulation and pharmacovigilance of ocular cyclosporine A-based products. CONCLUSIONS: Medical practice surrounding ocular cyclosporine A use in European Union nations differs based on variations in concentration, dosage, prescription indication, formulation, availability and distribution, manufacturing, quality, and regulatory monitoring.

An 8-year longitudinal analysis of UK ophthalmic publication rates.

Purpose44.5% of abstracts presented at biomedical conferences are published. 26.5% of abstracts presented are basic science. The 2005 Walport Report reformed clinical academic training in the United Kingdom (UK) to promote trainee research. This study aims to analyse UK Ophthalmology research output following the reconstruction of clinical academic training.Patients and Methods1862 abstracts presented at The Royal College of Ophthalmologists' (RCOphth) Annual Congress from May 2005-May 2012 were examined using PubMed. Publication trends were analysed using SPSS v22 (IBM), using Spearman's rank coefficient and Mann-Whitney U test.Results44 (2.4%) abstracts were randomized controlled trials (RCTs), 88 (4.7%) basic science, and 231 (12.4%) oral presentations. 486 (26.6%) abstracts were published to a mean impact factor (IF) of 2.39 (95% CI 2.21-2.57). Mean time to publication from presentation was 15.17 (13.88-16.48) months, negatively correlating with IF (r=-0.149, P<0.003). Oral presentation (P<0.0001), RCTs (P=0.002), and basic science (P<0.0001) abstracts all made publication significantly more likely, with hazard ratios of 2.63 (2.13-2.24), 2.07 (1.3-3.2), and 1.92 (1.41-2.59), respectively. Higher IF was associated with oral presentation (3.4 vs 2.16, P<0.0001), basic science (3.57 vs 2.35, P<0.0001), and RCTs (4.78 vs 2.38, P=0.002). No significant change in publication rate was seen across the 8 years (P=0.61).ConclusionThe proportion of basic science and total abstracts published that are presented at the RCOphth is lower than that in other biomedical conferences. RCTs, basic science abstracts, and oral presentations are more likely to be published. There was no improvement in publication rates following the 2005 Walport Report.

Changing trend in the utilisation rate of donated corneas for keratoplasty in the UK: The North East England Study.

PurposeTo report the changing trend in the utilisation rate of donated corneas for keratoplasty and to examine the reasons for unutilised corneas in the North East of England.MethodsRelevant data were retrospectively collected from a local eye retrieval database and the UK Transplant Registry for two separate years; namely, 2006 and 2010.ResultsThe utilisation rate of donated corneas for keratoplasty improved from 57% (52/92) in 2006 to 71% (220/312) in 2010 (P=0.012). Over the same period, there was a marked reduction of failed serological test results from 24% (22/92) to 5% (14/312) (P<0.001). The leading reasons for unutilised corneas were failed serological test results (22/92, 24%) in 2006 and inadequate tissue quality (23/312, 7%) in 2010. The rate of tissue contamination remained similar between 2006 (4%) and 2010 (6%) (P=0.80). Eleven (4%) corneas were not transplanted due to recipient-related factors in 2010. Donor corneas of inadequate tissue quality were associated with older age (P=0.04) but not with gender, donation site, consent method, death-to-enucleation interval, death-to-processing interval, and storage time in the eye bank.ConclusionThere was a substantial improvement in the utilisation rate of corneas donated in the North East of England between 2006 and 2010. The principal reason was a reduction in failed serological test results. High donor age was associated with increased chance of corneas not being used. Utilisation rate of corneas can be further improved if potential modifiable factors are addressed, such as recipient-related factors and microbial contamination.

Impact of telephone consent and potential for eye donation in the UK: the Newcastle Eye Centre study.

AIMS: To examine the impact of telephone consent introduced in 2007 on the eye donation rate and to report the changing trend and potential for improvement in eye donation in Newcastle upon Tyne, UK. METHODS: Relevant data were retrospectively collected from the local eye retrieval database for two separate years, namely, 2006 (before the introduction of telephone consent) and 2010. All the hospitals within Newcastle were included in the study. RESULTS: From 2006 to 2010, there was a 3.5-fold increase in eye donation from 32 (of 2479 deaths) to 111 donors per year (of 2213 deaths) in Newcastle (P<0.001). Consent was obtained via face-to-face interview in all 32 (100%) and 59 (53.2%) donors in 2006 and 2010, respectively. Introduction of telephone consent increased the donation rate by an additional 88.1% (from 59 to 111 donors) in 2010 (P<0.001). In addition, there was a significant increase in medical notes of the deceased being reviewed from 27.1% (671/2479 cases) in 2006 to 62.4% (1382/2213 cases) in 2010 (P<0.001). Acceptance rate of eye donation was 45.7% (32/70) in 2006 and 49.6% (111/224) in 2010 (P=0.575). Acceptance rate was positively associated with registration on organ donor register (P<0.001) and telephone consent (P<0.001), but not with age (P=0.883), gender (P=0.234), or location of death (P=0.984) of the potential donors. CONCLUSION: There has been a substantial improvement in eye donation rate in Newcastle over the recent years. Introduction of telephone consent and high-quality eye donation service serve as effective measures for increasing eye donation.

Do topical ophthalmic corticosteroids suppress the hypothalmic-pituitary-adrenal axis in post-penetrating keratoplasty patients?

PURPOSE: To establish whether hypothalmic-pituitary-adrenal axis suppression is possible secondary to long-term topical ophthalmic corticosteroid use in patients who have undergone penetrating keratoplasty (PKP). METHODS: Patients who had undergone a PKP and had been using corticosteroid-based eye drops continuously for more than 6 months, with no history of concomitant steroid (oral, inhaled, or cutaneous) use, were included within the study. A low-dose short Synacthen (LDSST) test was performed in each patient followed later by a short Synacthen test (SST). The mean SST and LDSST after 30 min were calculated along with their corresponding 95% confidence intervals (CIs). Correlation between both baseline SST and baseline LDSST with duration of treatment was determined using Spearman's correlation. RESULTS: In all, 20 patients were included within the study. The mean duration treatment was 28.2 months (range 11-96 months). All patients had normal baseline cortisol levels in both SST and LDSST tests. The mean 30 min SST was 753.8 nmol/l (95%CI: 696.6 nmol/l, 811.0 nmol/l) and no patients displayed inadequate adrenal response. The mean 30 min LDSST was 709.8 nmol/l (95%CI: 665.1 nmol/l, 754.5 nmol/l) and only one patient had an inadequate adrenal response. There was no correlation between baseline SST or LDSST and duration of treatment. CONCLUSIONS: This study found no evidence that patients using continuous long-term corticosteroid eye drops after PKP experienced inadequate adrenal response. We did not find any evidence of a negative correlation between length of treatment and SST or LDSST measurements at baseline.

Teor e composição química do óleo essencial de Hyptis marrubioides Epling (Lamiaceae) em diferentes genótipos / Essential oil content and chemical composition in Hyptis marrubioides Epl. of different genotypes

Hyptis marrubioides Epling (hortelã-do-campo) é espécie de uso medicinal conhecida pelas suas atividades contra infecções gastrointestinais, infecções de pele, dores e câimbras. Objetivou-se com este trabalho, avaliar o teor e composição química do óleo essencial de H. marrubioides em diferentes genótipos (roxo e branco) e partes da planta fresca (folhas, inflorescências e caule). Os genótipos estudados foram identificados através das inflorescências das plantas que apresentam coloração roxa e branca. O delineamento experimental foi inteiramente casualizado, contendo as três partes da planta de ambos os genótipos, perfazendo um fatorial 3x2, com quatro repetições. O óleo essencial foi extraído por hidrodestilação por duas horas e analisado por Cromatografia Gasosa acoplada a Espectrometria de Massas (CG-EM). O maior teor de óleo essencial foi observado na inflorescência do genótipo roxo. A composição do óleo essencial de H. marrubioides variou quantitativamente entre as partes das plantas analisadas e entre os genótipos. O composto α-tujona apresentou a maior porcentagem de área do pico nas inflorescências de genótipo roxo. As porcentagens das plantas com genótipo roxo foram em média superiores às plantas com genótipo branco.

Hyptis marrubioides Epling ("hortelã-do-campo") is a medicinal species known for its activities against gastrointestinal and skin infections, pains and cramps. The aim of this work was to evaluate essential oil content and chemical composition in H. marrubioides of different genotypes (purple and white), as well as fresh plant parts (leaves, inflorescences and stem). The studied genotypes were identified based on the inflorescences, which are purple and white. The experimental design was completely randomized, including the three parts of both genotypes, in a 3X2 factorial arrangement, with four replicates. Essential oil was extracted through hydrodistillation for two hours and analyzed using Gas Chromatography attached to a Mass Spectrometry (GC-MS). The highest essential oil content was found for the inflorescence of purple genotype. Hyptis marrubioides essential oil composition quantitatively varied among the analyzed plant parts and between genotypes. The compound α-thujone had the highest percentage of apex area in inflorescences of purple genotype. The percentages of purple genotype were on average higher than those of white one.

Association of the heart fatty acid-binding protein gene with quality of carcass and meat traits in pigs / Associação entre o gene da proteína de ligação de ácidos graxos - coração com características de carcaça e qualidade da carne em suínos

The heart fatty acid-binding protein (HFABP) gene was sequenced in parental animals of a F2 crossing of boars of the Brazilian native Piau breed with commercial sows (Landrace x Large White Pietrain). Primers used for PCR were designed to amplify four exons of the gene. The PCR products were sequenced and compared with the GenBank sequences. Differences between the generated sequences and the GenBank sequences were observed for both genetic groups. A total of 246 F2 animals were genotyped using the Hinf I restriction enzyme. Two genotypes were identified, 198 being animals HH and 48 Hh. The Hinf I SNP was significantly associated with weights of loin (bone-in) (P<0.05), jowl (P<0.05), sirloin (P<0.10), and kidneys (P<0.01). These results showed the potential of the H-FABP gene in marker-assisted selection programs for carcass traits in pigs.

O gene da proteína de ligação de ácidos graxos - coração foi seqüenciado em animais parentais de um cruzamento F2 entre varrões da raça nativa brasileira Piau e fêmeas comerciais (Landrace x Large White x Pietrain). Os primers utilizados na reação em cadeia da polimerase foram desenhados para amplificarem os quatro éxons do gene. Os fragmentos amplificados foram seqüenciados e comparados com a seqüência do gene depositada no GenBank. Foram observadas divergências entre as seqüências geradas e as do GenBank para ambos os grupos genéticos. Foram genotipados 246 animais F2 utilizando-se a enzima Hinf I. Dois genótipos foram identificados, sendo 198 animais HH e 48 animais Hh. O polimorfismo apresentou efeito sobre o peso total do carré (P<0,05), o peso da papada (P<0,05), o peso do filezinho (P<0,10) e o peso dos rins (P<0,01). Os resultados indicam que o gene da H-FABP apresenta potencial para aplicação em programas de seleção assistida por marcadores moleculares em suínos.

Postkeratoplasty emergency visits--a review of 100 consecutive visits.

PURPOSE: Preoperative counselling for penetrating keratoplasty should include awareness of symptoms and signs of possible complications as early presentation can enhance long-term success. In our corneal transplantation service, all patients are routinely instructed to arrange a same day emergency visit through a dedicated telephone line if they experience any symptoms in eyes that have undergone keratoplasty. This study was designed to evaluate the reason for presentation, management outcome of each visit and the efficiency of the system in management of postkeratoplasty complications. METHODS: A review of 100 consecutive emergency visits by postpenetrating keratoplasty (PKP) patients in a tertiary eye care centre was included. RESULTS: Sixty-two patients with varied preoperative diagnoses presented during the review period. Sixteen visits were within the first month after surgery and 40 visits within the first year. Ten patients (16%) sought consultation more than twice during the study period with one patient presenting five times. Pain and grittiness were the main presenting symptoms (68%). Loose corneal suture (25%) necessitating removal was the most common diagnosis. Sixteen visits resulted in hospital admission for treatment. The graft survived in all patients and the visual acuity was preserved in 95% of our patients. CONCLUSION: Most corneal surgeons educate their patients to seek prompt treatment for symptoms such as redness, sensitivity to light, loss of vision, pain, or any other symptoms in eyes that have undergone keratoplasty. Early intervention of sight threatening complications increases the chance of graft survival and best-obtained vision. This review shows a simple open access system facilitates early presentation and successful management of postgraft complications.

Comparison of the effect of sodium hyaluronate (Ophthalin) and hydroxypropylmethylcellulose (HPMC-Ophtal) on corneal endothelium, central corneal thickness, and intraocular pressure after phacoemulsification.

PURPOSE: To prospectively evaluate the effects of 2% hydroxypropyl-methylcellulose (HPMC-Ophtal) and sodium hyaluronate 1% (Ophthalin) on intraocular pressure, corneal thickness, and endothelial cell loss in small incision cataract surgery with implant. METHODS: A total of 110 patients undergoing routine phacoemulsification with implant received either 2% hydroxypropyl methylcellulose or sodium hyaluronate 1% as ophthalmic viscosurgical device. Pre- and postoperative slitlamp examination, intraocular pressure measurement (preoperatively and at 1-4 hours, 1 day, and 7 days postoperatively), ultrasonic pachymetry (preoperatively and at 1 week, 4-6 weeks, and 12 weeks post operatively), and corneal endothelial cell count (preoperatively and 12 weeks postoperatively) were performed. Data were analyzed using two-way analysis of variance. RESULTS: All measurements were comparable between the two groups preoperatively. Intraocular pressure was significantly lower in the Ophthalin group at 1 day post operatively, while no significant difference was found between the two groups on the 1-4 hours and 7 days examination. The central corneal thickness was not significantly different between the two groups at any postoperative visit . However, the mean cell density demonstrated a significant fall of 11.76% for Ophthalin and 4.27% for HPMC-Ophtal at 12 weeks post-operatively, the difference between the two being significant (p=0.009). CONCLUSIONS: 2% Hydroxypropyl methylcellulose, compared with sodium hyaluronate 1%, is superior in protecting the corneal endothelial cells, has the same effect on central corneal thickness, and is associated with slightly higher intraocular pressure 1 day post operatively. It compares favorably with sodium hyaluronate 1% and can be used as an effective and cheaper alternative in routine small incision cataract surgery with implant.

Development of organised conjunctival leucocyte aggregates after corneal transplantation in rats.

AIM: To investigate the development of lymphoid aggregates in the conjunctiva after corneal transplantation in rats. METHODS: LEW or PVG strain corneas were transplanted orthotopically to PVG rats. Cornea and conjunctiva were examined clinically for up to 42 days. Eyes were removed with attached conjunctiva on days 10 and 15 after transplantation (before and during rejection), together with normal eyes, fixed, paraffin embedded, and examined immunohistochemically. RESULTS: Clinically, the temporal half of the upper palpebral conjunctiva of recipients of 10/19 allografts and 1/10 isografts developed pronounced swelling, correlating with inflammation and rejection. Histologically, the swelling comprised leucocytic aggregates with an altered overlying epithelium. Aggregates contained granulocytes, macrophages, and cells expressing major histocompatibility complex (MHC) class II, CD4, and CD8, all more numerous in allograft associated conjunctiva. Class II+ cells were more abundant at the surface, whereas macrophages and T cells were more numerous in the deeper stroma. There were few B cells. There was greater CD54 expression by vascular endothelium in allograft associated aggregates. Cells expressing TNFalpha and IFNgamma but not IL1beta were present in stromal and superficial areas. CONCLUSIONS: Corneal transplantation in rats induces the development of organised conjunctival leucocytic aggregates in a fixed location that are significantly more pronounced in recipients of allografts compared with isografts and show characteristics of a Th1 type immune response. These aggregates have characteristics of conjunctiva associated lymphoid tissue and may be sites of presentation of graft antigens and lymphocyte proliferation at the ocular surface.

A randomised, crossover, multicentre study to compare the performance of 0.1% (w/v) sodium hyaluronate with 1.4% (w/v) polyvinyl alcohol in the alleviation of symptoms associated with dry eye syndrome.

AIMS: To assess the safety and performance of a 0.1% (w/v) solution of sodium hyaluronate (HA, Fermavisc, in the alleviation of symptoms of severe dry eye in comparison with a 1.4% (w/v) solution of polyvinyl alcohol. METHODS: A randomised, crossover, multicentre study carried out at eight centres in the UK. Eligible patients giving written informed consent were randomised to the order in which they would receive the two study products. Each treatment period lasted for 4 weeks, then the patient crossed over to the other study product. Symptoms of burning and grittiness were assessed by visual analogue scale (VAS) at each study visit and other objective clinical assessments of ocular structure and function were carried out at baseline and the end of each treatment period. RESULTS: Thirty-nine patients were entered into the study and 32 completed both treatment periods and were included in the statistical analyses. A significant improvement in the patients' VAS assessment of burning was seen after treatment with HA (P = 0.03, 95% Confidence Interval: -23.5 to -1.1). This treatment also resulted in a significantly lower rose bengal staining score (P = 0.04, 95% Confidence Interval: -1.62 to -0.05 for the right eye). CONCLUSION: The results show a significant clinical benefit in terms of relief of the symptom of burning when HA is applied topically to the eye three or four times per day or as required. HA also appears to have a protective effect on the corneal epithelium, as shown by a reduction in the level of staining of corneal epithelial cells by rose bengal. This study confirms that Fermavisc is a safe and effective product for use in the alleviation of symptoms of severe dry eye syndrome.

Tumor necrosis factor-alpha and interleukin-1beta mediate the production of nitric oxide involved in the pathogenesis of ifosfamide induced hemorrhagic cystitis in mice.

PURPOSE: We investigated the participation of nitric oxide in ifosfamide induced hemorrhagic cystitis in mice, and the involvement of tumor necrosis factor (TNF)-alpha and interleukin (IL)-1beta in the induction of nitric oxide production in this model. MATERIALS AND METHODS: Hemorrhagic cystitis was induced in mice by 100 to 400 mg./kg. ifosfamide and evaluated 6, 12, 24 or 48 hours thereafter by certain parameters, including vesical edema measurements, microscopic analysis and immunohistochemical testing for inducible nitric oxide synthase. Ifosfamide injected mice were pretreated with 10 to 40 mg./kg. of the nitric oxide synthesis inhibitor L-NG-nitroarginine methyl ester, 80 mg./kg. of mesna, a chemical antagonist of acrolein and the urotoxic metabolite of ifosfamide, 50 microl. antiserum against TNF-alpha and IL-1beta per mouse, 45 mg./kg. of the selective TNF-alpha synthesis inhibitor thalidomide or 200 mg./kg. of the TNF-alpha and IL-1beta synthesis inhibitor pentoxifylline. RESULTS: Ifosfamide induced vesical edema, which peaked 12 hours after ifosfamide injection. Microscopic analysis revealed vascular congestion, edema, hemorrhage, fibrin deposition, neutrophil infiltration and epithelial denudation. Inducible nitric oxide synthase immunolocalization demonstrated intense reactivity to inducible nitric oxide synthase in the cytoplasm of bladder epithelial cells, which showed diffuse necrosis. Pretreatment with mesna reduced the increases in vesical edema, while treatment with L-NG-nitroarginine methyl ester, antiserum to TNF-alpha or IL-1beta, thalidomide or pentoxifylline inhibited vesical edema and microscopic alterations. Antiserum treatments also inhibited the expression of inducible nitric oxide synthase in the urothelium. CONCLUSIONS: Nitric oxide produced by inducible nitric oxide synthase is involved in urothelial damage and in the inflammatory events leading to hemorrhagic cystitis after ifosfamide administration in mice. The induction of inducible nitric oxide synthase in the urothelium appears to depend on the synergistic effect of IL-1beta and TNF-alpha.